Stocks swooned Wednesday after Federal Reserve Chairman Jerome Powell said the novel coronavirus is creating lingering uncertainty for the U.S. economy while scoffing at the notion that negative interest rates could help the world's largest economy regain its footing.

The remdesivir news took precedent over headlines about first-quarter GDP, which contracted 4.8%, or the worst shrinkage experienced by the world's largest economy since the dark days of the global financial crisis.